Elastic axle for motor vehicles



Sept. l, 1925.

2 Sheets-Sheet 2 Ll h1--- E BUGATTI ELASTIC AXLE FOR MOTOR VEHICLES Filed Oct 5, 19;*3

Patented Sept. 1, 1925.

UNITED STATES ETTORE BUGATTI, or MoLsHEIM, FRANCE.

ELSTIC AXLE FOR MOTOR VEHICLES.

Application led October 5, 1923. Serial No. 666,768.

To aZZ whom t may conc-cm: t

Be it known that. I, ETTORE BUGATTI, asubject of the King of Italy, and a resident of Molsheim, Bas-Rhin Department, France, have invented certain new and useful Improvements in Elastic Axles for Motor Vehicles; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the salme, reference being had to the accompanying drawings, and to letters or figures or' reference marked thereon, which form apart of this specification. Y

Vehicle axles yof the known types consist as a general rule'of forged pieces which are secured to the vehicle frame by semi-elliptical'springs or l@ elliptical springs.

This arrangement oiiers a drawback from the fact that the deformations ofthe spring due to the inequalities of the road will produce displacements or the axle in the horizontal plane, and this may cause much prejudice to the steering gear.

Further, the breakage of a main spring plate is always to be apprehended, and this may produce fatal accidents. Y

My invention relates to an "axle combinatio-n whereby such drawbacks may be eliminated, and the irregularities of the road ca-n no longer affect the position of the front axlein its horizontal plane, whilst the axle is free to move in thevertical plane.

In vthis invention, the axle consists essentially of a U-shaped element wherein is disposed thef front lcross-piece of the vehicle frame; between the flanges of said .crosspiece and those of the axle are disposed along the whole length of the axle, and above and below, a certain number of spiral springs which serveV the purpose of the usual plate springs. Y.

n A. suitable guiding device further connects the middle part of the axle with said crosspiece, so that all transverse displacement or vplay of the axleV with respect to the vehicle frame will be prevented.`

Shock-absorbers can also be providedfor the braking of the motion of the axle relative tothe cross-piece, the said shock-absorbers consisting for example of discs havingbetween them the vertical web of the axle, said discs being pressed by means of a device with adjustable pressure such `as ak spiral spring.

rlhe present invention further relates to the following improvements in the said axle arrangements a.-I`he front cross-piece of the vehicle frame has a U-shape and partially surroundsy the axle, according to an arrangement which 1s the inverse of the one above indicated.

19.*The axle is guided inits movement by means of bosses movable in vertical slots in the said cross-piece, the said bosses being secured to cheeks assembled by an axle or spindle extending through the vehicle axle and having the latter pivoted thereon.

, cfr-One or more plate springs or undulated springs are interposed between the said cross-piece and the vehicle axle.

` The application to the rear axle of the vehicle of an arrangement analogous to what is employed for the front axle.

The 'devices for damping the motion of the axle consist of the cheeks referred to in paragraph (o), the friction surfaces of the y damping device being formed. by the internal face-s of the cheeks, the internal and externalv faces of both walls of the cross-piece, anl the front and rear facesY of the vehicle ax e.

.The following description and appended drawings which lare given by way of example set forth the present invention.

Figs. 1 and 2 are diagrams, 'respectively in elevation and plan, relative to the known arrangements.

Fig. 3 1s a front elevation of a front axle according to the invention, with certain parts removed.

Fig. 4: is a planview of the same, with the wheels removed.

F ig. 5 is a front view of the axle alone.

F ig..6 is a transverse section on the line l and `2, by means of `semi-elliptical springs 3 whereof one end is secured to the vehicle frame at 4 and the other is attached to a shackle 8.

lVhen the right and lett hand springs 3 are subjected to deformation under the etfect of a temporary overload -or discharge of load due to the inequalities of the road, the points 6 at which the springs 'are 'attached to' the axle will each be displaced on an arc ot' a` circle-having the point 4 as a centre, Fig. 1, the point G being moved `forward when "the spring "is released and moved Vbackward when itis bent.

In lthese conditions, it it be supposed that the 'lett hand wheel is raised and the right hand wheel lowered, the point at which the axle is attached lto 'the lett hand spring will be Vmoved backward andthe corresponding point 'for the right hand spring will be moved forward, oso that the axle 1 will 'Yas- ,sume lthe `position shown inthe mixed lines, F 2, in which the wheels are slightly turned towards the lett.

rlliese changes in the shape of the spring will thus `tend to turn the vehicle about, so th-at an ellort must lbe constantly exerted upon the steering gear in order to follow a straight line; t-liis fdifawlback is but little apparent at slow speeds, but it becomes a source or great langer at high speeds, and 'the driver 'must be in constant movement for this reason, and further, the drawback cannot `be o'bviated Veven Aby the use of the most ,powerful shock-absorbers'.

In my invention, fthe vehicle axle consists essentially a sheet metal element 11 having a .general lll-shape in transverse section and the form ot' a solid ot unifiorin strength in the lengthwise direction; to each end of -said axle are riveted the forged pieces 12 which are adapted to receive the journal 13 and the t-runnions.

lVithin the said axle is disposed-the front trame cross-.piece vl-lsecured tothe ends ot 'the longitudinals 23, andthe spiral springs 15 are disposed between the said cross-piece and Vthe Taxle, above and .below the crosspiece.

It is to be observed that the oscillations ot 'the Vfront axle occasioned by the inequalities of the wground will take place in the original vertical plane ol the-axle; it it `be supposed 'that the 'le'it hand wheel is raised, Fig. 10, whilst the rightfhand wheel 'is lowered s(designating "by right and lefthand the wheels respectively at the right and lett hand ot the driver)4 t-he lower end springs on the right and the upper end springs on 'the left will be compressed, as

"observed, tlius 'producing a resistance f couple which tends to -rest-oicvthe spring to the normal position of equilibrium.

In the case in which both wheels are raised'at'tlie sametinie, -allitlie lower springs will be expanded'a'nd Va`lltlie upper springs compressed, and this will also tend to bring the axle into theoriginal position.V

As shown in Figs. 3, 6 and 7, in order that the axle move in a vertical or angular manner with respect to the vehicle trame, whilst all lateral displacement is prevented, suitable guiding means are used to connect :the 'middle ot' the axle with t-he middle of the front cross-piece, and said means may have 'the following construction.

To the cross-piece 14: is riveted a sleeve Q2 (into which can be inserted the axle of the engine-starting handle) and which has revoluble thereon the 'disc 1G which bears upon the rear `face of the axle 11; -a second disc 17 bears upon the other face of the said axle, and is pressed thereupon by a regulating spring 18 which is covered by a cap 19 and is held by a nii-t E20.

Bis shown in Figs. 8 and 9, lthe disc 1G has at lthe middle an oblong projecting portion 161 having the parallel vfaces 16.J and 'fitting into a slotlot like Yform '21 provided in the vertical cheek of Ithe axle 11 and slidabile in Athe latter, VFig. 3. The projecting portion 16, prevents all lateral displacevieiit or play ot the said axle, vbut Athe latter is enabled 'to n'io'vein 'the x'fertical direction due to `tlie slida'ble arrangement, as well as inthe angular direction, Fig. 10, 'in which case the disc v16 turns upon the lsleeve 22. The aggregate or the discs 1G and 17 also constitutes acentral shock absorber ot Ythe `trictif'jn type 'by reason 'o'ic the pressure 'of the discs, "t-hus braking the movements of the axle with 'respectto the cross-piece.

At each side of the vcentral 'shock-absorber maybe disposed one or more ylateral'-sli'ockabsorbers ot analogous construction, whereof one is 'shown in Fig. 7, kcomprising as before the two 'disc-s 16, l17 having b'eltween/'them the cheek of A`the axle, but the disc l'lfdo'es not serve asa guiding member, and hence it'can *be rivetetltothe crosspiece 1L1,th'eaxle`22Ill extendinglloosely, with 'a certainyplay, `through an aperture 421a ot 'the cheek of vthe said 4velricle axle, 'so "as 1lto provide for the angular 1motion ofthe latter The principal advantages o'f-the axlearrangement according to 'the linvention are as follows:

1. Elimination oi" jarring transmitted lto the steering gear'bv the rearward displacements ot the front vehicleax'le which in my invention can only niove ina `verticali plane. 2. The weight Vot ythe whole axle device ris much reduced.

8. All dangerot accident iomthe breakage of a main spring plate is eliminated.

4. The -said axle piece can `be manufacturedby the rolling process with Etacility.

5. The shock absorbers can be mounted without drilling the vehicle frame torlthis purpose,and all weaken'ingot the 'longitudi- Vnals isthus avoided.

Obviously, the arrangements hereinbefore ond disc so as to constitute a shock-absorbing described by way of example are not limitative, and are subject to modifications without departing from the principle of the invention. n

In particular, the said main axle may have a profiled shape and may be disposed in a casing whose outline is shown in the broken lines, F ig. 6, and this will be advantageous for racing vehicles.

Vhat I claim is 1. The combination with a vehicleframe having an end cross piece; of a profiled U- shaped member in which said piece is inclosed, Wheel mounting means rigidly secured to the end of said member beyond the ends of said piece, means to yieldingly support the member on said piece and means to constrain said member to move vertically with respect to said piece.

2. The combination with a vehicle frame having an end cross piece; of a profiled U- shaped member in which said piece is inclosed, wheel mounting means `rigidly secured to the end of said member beyond the ends of said piece, means to yieldingly support the member on said piece, means-to constrain said member to move vertically with respect to said piece and means secured to said piece to damp the vertical movements of the member.

3. An axle for motor vehicles consisting of a profiled member of U or like shape wholly or partially surrounding the cross-piece of the vehicle frame and forming the axle properly so called, an elastic device interposed between theisaid cross-piece and the vehicle axle above'and below the said crosspiece, a spindle secured to the middle of the cross-piece of the vehicle frame and extending in the longitudinal direction of the vehicle, a disc revoluble upon said spindle, a boss provided upon said disc which engages in a slot formed in the main body 'of the said axle and is Aslidable therein.

4. An axle for motor vehicles consisting of a profiled member of U or like shape wholly or partially surrounding the cross piece of the vehicle frame and forming the axle properly so called, an elastic device interposed between the said cross-piece and the vehicle axle above and below the said crosspiece, a spindle secured to the middle of the cross-piece of the vehicle frame and extending in the longitudinal direction of the vehicle, a disc revoluble upon saidspindle, a boss provided upon said disc which engages in a slot formed in the main body of the said axle and is slidable therein; a second disc mounted upon said spindle in such manner that the said axle shall be maintained between the first-mentioned disc and the secdevice.

5. An axle for motor vehicles consisting of a profiled member of U wholly or partially surrounding the crosspiece of the vehicle frame and forming the axle properly so called, an elasticv device interposed between the said cross-piece and the vehicle axle above and below the said cross-piece, a spindle secured to the middle of the cross-piece of the vehicle frame and extending in the longitudinal direction of the vehicle, a disc revoluble upon saidk spindle, a boss provided upon said disc which engages in a slot formed in the main body of the said axle and is slidable therein; a second disc mounted upon said spindleV in such manner that the said axle shall be maintained between the irst-mentioned dise and the second disc so as to constitute a shockabsorbing device, and two discs secured to the ends of the said cross-piece and constituting a shock-absorbing device at each end of the same.

6. The combination withja vehicle frame having an end cross piece; of an axle member U-shaped in section inclosing said piece and having its web vertical, cushioning devices between said piece and the flanges of said member and means to constrain said member to move vertically with respect to said piece while permitting rotation in the vertical plane, y l

7. The combination with a vehicle frame having an end cross piece; of an axle member U-shaped in section inclosing said piece and having its web vertical, cushioning devices between said piece and the flanges of said member, means to constrainsaid member to move vertically with respect to said piece while permitting rotation in the vertical plane, and means to damp the vertical and rotating movements of the member.

8. The combination with a vehicle frame having an end cross piece; of an axle member having a U-shaped section and inclosing said piece. the web of said member being vsubstantially parallel to the outer face of.

said piece, wheel mounting means secured to the ends of said member beyond the ends of said piece, springs between the two anges of said member and said piece, a sleeve secured to said piece and projecting through said member, and adjustable friction devices constraining said member to movements in substantially a vertical plane and damping the movements of the member.

In testimony that I claim t-he foregoing as my invention, I have signed my name hereto. f

ETTORE BUGATTI@ or like shape n 

